To unlock the following Evolved Bakugans, first complete Story mode. Then, perform the corresponding tasks:

EVOLVED BAKUGAN - HOW TO UNLOCK
Battle Axe Vladitor - Defeat Marduk without giving up any cards.
Blade Tigrerra - Defeat Runo in a Battle Royal.
Delta Dragonoid II - Defeat Dan in a Battle Royal.
Dual Hydranoid - Defeat Masquerade in a Battle Royal.
Hammer Gorem - Defeat Julie in a Battle Royal.
Preyas II - Defeat Marucho in a Battle Royal.
Storm Skyress - Defeat Shun in a Battle Royal.